Data: 2023 USDA zones (PRISM/OSU) · NOAA 1991–2020 normals · updated Oct 29, 2026

Planting zone for 84665 — Sterling, UT

ZIP code 84665 (Sterling, Sanpete County) is in USDA zone 6a: the coldest winter night averages −10 to −5 °F. The median last spring frost is May 11 and the first fall frost October 6.

Where ZIP 84665 is

Outlined: the ZIP code area · tap the map for the zone at any spot · scroll or pinch to zoom

Not the official USDA Plant Hardiness Zone Map. Zones come from the 2023 USDA hardiness-zone data by the PRISM Group, Oregon State University; we re-mapped and recolored them. The official map is at planthardiness.ars.usda.gov.

Zone6a−10 to −5 °F

Coldest night−23.3 to −20.6 °C

Last frostMay 11

First frostOct 6

2012 zone6a

Same zone as on the 2012 map. The zone is the one at the center of the ZIP code; hilly ZIPs can span two zones. What zone 6a means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Sterling, UT…

Forecast data: National Weather Service (api.weather.gov), public domain. This is not a warning service — for official frost and freeze warnings see weather.gov.

Frost dates in Sterling, UT

JanFebMarAprMayJunJulAugSepOctNovDec

Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free

Last spring frostMay 11median — 50% chance of a later frost

Safe for tender plantsJune 1only 10% chance of frost after

First fall frostOctober 6median — 10% chance by Sep 24

Growing season146 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 26 and returns around October 16.

From the NOAA station Manti, UT — 4 miles away, elevation 5,742 ft. NOAA NCEI U.S. Climate Normals 1991–2020, 32 °F threshold. Low spots and valleys can freeze later in spring than the station.

When to plant vegetables in 84665

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Mar 30 – Apr 13

SpinachSow outdoors · Mar 30 – Apr 20

Broccoli, cabbageStart indoors · Mar 2 – Mar 16

Broccoli, cabbageTransplant · Apr 20 – May 4

Onion setsPlant outdoors · Apr 13 – Apr 27

PotatoesPlant outdoors · Apr 20 – May 4

LettuceSow outdoors · Apr 13 – Apr 27

Carrots, beetsSow outdoors · Apr 20 – May 4

TomatoesStart indoors · Mar 16 – Mar 30

TomatoesTransplant · May 18 – Jun 1

Peppers, eggplantStart indoors · Mar 2 – Mar 16

Peppers, eggplantTransplant · May 25 – Jun 8

BeansSow outdoors · May 18 – Jun 1

Sweet cornSow outdoors · May 18 – Jun 1

Cucumbers, squashSow outdoors · May 18 – Jun 1

Fall lettuce, spinachSow outdoors · Aug 11 – Aug 25

GarlicPlant cloves · Sep 22 – Oct 27

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (May 11) and first fall frost (Oct 6) with the rules of thumb U.S. extension services publish. Cool-season crops take a light frost; warm-season crops do best once the soil is above about 60 °F.

When spring arrived in 2026

In 2026, spring leaf-out near 84665 came on Mar 23 — 20 days earlier than the 1991–2020 average (Apr 12).

average
Apr 122026
Mar 23

JanFebMarAprMayJun

The Spring Index marks the day when accumulated warmth is enough for lilac and honeysuckle to leaf out — a widely used signal that the growing season has started. Source: USA National Phenology Network, www.usanpn.org — Spring Indices, first leaf, 2026 (data as of 2026-09-08) and 30-year average 1991–2020 (CC BY 4.0).

Native plants for zone 6a in Utah

546 plants native to the lower 48 states, recorded in Utah, and rated by the USDA to survive −10 °F or colder — the bottom of zone 6a. Each links to its USDA PLANTS profile.

Source: USDA, NRCS. 2026. The PLANTS Database (plants.usda.gov), National Plant Data Team — state distribution, native status and the “Temperature, Minimum” characteristic. Check light, moisture and soil needs before buying; local nurseries and your state native plant society can confirm what thrives in Sterling, UT.

Soil in Sterling, UT

The soil mapped at the center of ZIP 84665 is Faim family — gravelly clay loam, well drained.

TextureGravelly clay loamholds water and nutrients; slow to drain and warm up

pH6.7neutral; most vegetables like 6.0–7.0

DrainageWell drainednatural drainage class

Organic matter3%moderate

Hydrologic groupDwater soaks in very slowly

Farmland classNot prime farmlandUSDA classification

Map unit: Faim-Clayburn-Castino families complex, 5 to 30 percent slopes.

Soil Survey Staff, Natural Resources Conservation Service, USDA. Soil Survey Geographic (SSURGO) Database, via Soil Data Access, accessed 2026-10-29. The soil at the center point of ZIP 84665; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Sterling, UT

Summer high87 °Faverage high, July

Winter low19 °Faverage low, January

Hot days18days a year at 90 °F or more

Freezing nights167nights a year at 32 °F or less

Growing degree days2,504base 50 °F — the season’s usable heat

Longest day14 h 56 mindaylight on June 21

Shortest day9 h 24 mindaylight on December 21

Onions to growIntermediateday-neutral types bulb best; long-day varieties may not bulb fully

Precipitation13.1 inper year, rain and melted snow

Snowfall53 inper year; 59 days with snow on the ground

Average high and low, by month

Precipitation by month inches · ❄ = snowfall

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Manti, UT (4 mi away); precipitation: Manti, UT (4 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

2 of the 8 nearest ZIP codes are in a different zone — elevation and distance from water change winter lows quickly.

Centerfield, UT · 12 mi

Utah planting zones →

Questions about 84665

What planting zone is ZIP code 84665?

ZIP code 84665 (Sterling, UT) is in USDA hardiness zone 6a on the 2023 map: the coldest night of an average winter reaches −10 to −5 °F (−23.3 to −20.6 °C).

When is the last frost in Sterling, UT?

The median last spring frost (32 °F) near 84665 is May 11; after June 1 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Manti station.

When is the first frost in Sterling, UT?

The median first fall frost near 84665 is October 6, giving a median frost-free growing season of 146 days.

When should I plant tomatoes in 84665?

Start tomato seeds indoors around Mar 16 – Mar 30 and set transplants outside around May 18 – Jun 1, one to three weeks after the median last frost.

How much rain and snow does 84665 get?

About 13.1 inches of precipitation a year and 53 inches of snowfall (NOAA 1991–2020 normals, Manti station).

How hot do summers get in Sterling, UT?

The average high peaks at 87 °F in July, with about 18 days a year at 90 °F or more.

What kind of soil does 84665 have?

The USDA soil survey maps Faim family at the center of ZIP 84665: gravelly clay loam, well drained, pH about 6.7 (neutral).

Did spring come early in Sterling, UT in 2026?

Spring leaf-out near 84665 came on Mar 23 in 2026, 20 days earlier than the 1991–2020 average (Apr 12), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Sterling, UT?

Intermediate onions: the longest day near 84665 is 14 h 56 min, so day-neutral types bulb best; long-day varieties may not bulb fully.